[wp-hackers] how to create separate search function?

[Stefan Hartweg]

Hi,

I need to write a search plugin or hack  that's completely separate from the
existing search functionality of Wordpress (I think).
Basically I would like to use the existing search function as it is, but
have a second search function to search for matches after users have filled
out a brief questionnaire (this is a product based blog, so the users will
enter specific features of the product they would like and the search will
then only show them results matching their selections). I'm going to store
these features in custom fields.

So far I have found a few plugins, that search custom fields, but the
problem is that they EXTEND the existing search function. 

What I'm wondering now is how to write a separate search plug in or create a
hack (should I reuse some of the existing search functionality, etc) and
more importantly how to INTEGRATE such a plugin/hack, as I don't think there
will be an existing hook I can call such a plugin through?

Thank you for your input.

Steve